Neutrophils
Neutrophil Piranhas swarm in schools, attacking furiously. They live fast, die young, leaving behind cloudy waters (pus).
Macrophages
Macrophage Sharks patrol the reef endlessly, biting and swallowing anything suspicious. They also send signals in the water (cytokines = "blood scent") to call in reinforcements.
Microglia
Microglia Octopuses live deep in coral caves (the brain), wrapping intruders with tentacles and pruning old coral.
Natural Killer Cells
Natural Killer Electric Eels strike with sudden jolts, eliminating sick or rogue fish without hesitation.